1. Field of the Invention
A rehabilitation system that combines robotics and interactive gaming to facilitate performance of task-specific, repetitive, upper extremity/hand motor tasks, to enable individuals undergoing rehabilitation to improve the performance of coordinated movements of the forearm and hand is disclosed. More specifically, the rehabilitation system includes a two degree-of-freedom (DOF) robotic, upper limb rehabilitation system and interactive gaming hardware that is coupled to a computer, to provide a virtual reality-like environment.
2. Summary of the Prior Art
Stroke is a major cause of disability in the United States with approximately 800,000 new cases reported annually, of which about 150,000 die. Typically, there are over 4.5 million stroke survivors in the population at any given time. Limited motor recovery in the paretic upper limb accounts for a large share of the disabling sequelae. Indeed, only about a small percentage of stroke sufferers with initial complete upper limb paralysis ever recover functional use of the limb during their lifetime.
The physical effects of stroke are variable and may include impairment in motor and sensory systems, language, perception, emotional and cognitive function. Impairment of motor function usually involves paralysis or paresis of the muscles on the side of the body that is contralateral to the side of the brain lesion. Of all impairments that result from stroke, perhaps the most disabling is hemiparesis of the upper limb.
Population-based statistics indicate that between 73% and 88% of first-time strokes result in an acute hemiparesis of the upper and/or lower limbs. The upper limbs are of special concern because the impact of upper-extremity impairments on disability, independence, and quality of life is so marked. Consequently, improvement in motor abilities, and, more specifically, functional use of the upper extremity, is considered one of the primary goals in post stroke rehabilitation. However, even with rehabilitation, the functional recovery of arm and hand use is generally limited when compared with that of the lower extremities.
Traumatic brain and incomplete spinal cord injuries are other conditions that often leave patients with similar impairments and functional limitations. In both instance, the injury sustained is lifelong.
Traumatic Brain Injury (TBI) is a worldwide major public health problem. The Center for Disease Control and Prevention (CDC) estimates that 235,000 Americans are hospitalized annually with TBI and survive. Sadly, approximately 80,000 of these survivors—roughly one-third of the total—are left with long-term disability. An estimated 10,000 or more who sustain TBI, but are not hospitalized, also become disabled each year.
Long-term disability after TBI includes problems with motor control, i.e., weakness, spasticity, and instability; cognition, i.e., thinking, memory, and reasoning; sensory processing, i.e., sight, hearing, touch, taste, and smell; communication, i.e., expression and understanding; and behavior or mental health, i.e., depression, anxiety, personality changes, aggression, acting out, and social inappropriateness. The CDC estimates the prevalence of disability resulting from TBI in the U.S. to be 5.3 million. Moreover, the annual direct and indirect costs including those due to work loss and disability have been estimated at $60 billion. The incidence of TBI has been exacerbated by the conflicts in Iraq and Afghanistan where, tragically, TBI has become one of the most prevalent injuries among soldiers.
Spinal Cord Injury (SCI) requires on-going, multiple disciplinary efforts to stabilize, diminish or prevent secondary impairments and complications and to improve or maintain social role functioning and quality of life for the individual throughout the remainder of his/her life. There are approximately 250,000 persons with SCI in the United States, and an additional 10,000 sustain SCI injuries annually. The estimated annual national economic impact of SCI is about $9.73 billion.
Because the average age at time of an SCI is 32, specialized care is necessarily long-term. Persons with SCI have increasingly longer life expectancies, and as they age they risk developing secondary conditions. Over 50% of people with SCI have cervical injuries resulting in plegia of all four extremities (tetraplegia) leading to impairments in both mobility as well as independence in activities of daily living. Out of all cervical injuries leading to tetraplegia more then 50% are incomplete, resulting in paresis, which is the ability to perform impaired or inefficient movements.
Stroke/TBI/SCI survivors historically receive intensive, hands-on physical and occupational therapy to encourage motor recovery. However, due to economic pressures on the U.S. health care system, individuals are receiving less therapy and are being discharged from rehabilitation hospitals and clinics sooner than formerly was the case.
Robotic training is a new technology that shows great potential for application in the field of neuro-rehabilitation in either an in-patient or an out-patient setting. Robotic training has several advantages, e.g., adaptability, data collection, motivation, alleviation of patient safety concerns, and the ability to provide intensive individualized repetitive practice. Studies on the use of robotic devices for upper extremity rehabilitation after stroke have shown significant increases in upper limb function, dexterity and fine motor manipulations, as well as improved proximal motor control.
However, there are no available training devices that enable flexion/extension movements of the fingers and the hand in conjunction with supination/pronation of the forearm. These movements are synergistic and important to daily functional tasks such as eating, dressing, and grooming. Consequently, a robotic device that facilitates the performance of coordinated forearm pronation/supination movements and trains hand grasp/release movements would be highly desirable because recovery of these movements is a problem in the rehabilitation of individuals post stroke.